In one aspect, this invention relates to a supported noble metal catalyst composition. In another aspect, this invention relates to a selective diolefin (diene) hydrogenation process employing a supported noble metal catalyst composition. In still a further aspect, this invention relates to a process for the selective hydrogenation of 1,3-butadiene to butenes employing a supported noble metal catalyst composition.
Catalysts comprising palladium, silver and a support material are known diene hydrogenation catalysts. For instance, U.S. Pat. No. 4,409,410 discloses the use of a Pd/Ag/Al.sub.2 O.sub.3 catalyst for the selective hydrogenation of butadiene to butenes. Even though supported Pd/Ag catalysts are effective hydrogenation catalysts, there is an ever present need for further improvements (e.g., for enhanced selectivity to monoolefins and/or increased catalyst life.). The present invention is directed to an improved, modified catalyst compositions and its use in processes for the selective hydrogenation of diolefins to monoolefins, preferably of 1,3-butadiene to butenes.